Electric vehicles are typically driven by electric motors that rely on batteries for electrical power. Electricity may be supplied to the batteries for storage from a variety of different sources. For example, electricity may be supplied to the batteries of an electric vehicle by a charger that is plugged into an electrical transmission network (i.e. an electrical power grid), by electricity generated by an internal combustion engine, by electricity produced by regenerative vehicle braking, and/or by solar panels mounted on the electric vehicle.
Existing electric vehicles typically utilize a fixed ratio, single-speed transmission that provides one forward gear. Such electric vehicles are fitted with relatively large electric motors such that there is sufficient torque to launch the vehicle from a standing stop and enough power to drive the vehicle to highway speeds. These large electric motors require a large amount of electricity to properly operate. Accordingly, large arrays of batteries are generally required for extended operation of a conventional electric vehicle. The foremost limitation of electric vehicles is the cost and size of the batteries. Batteries are both heavy and expensive, thereby setting practical limits to the range of electrical vehicles. What is needed is a way to make electric vehicles more efficient such that the range can be increased without the need for additional batteries and their associated weight and cost trade-offs.